


Equilibrium

by dormantchrysalis



Series: Triad Closure [1]
Category: Marvel Cinematic Universe
Genre: Alpha Bucky Barnes, Alpha Steve Rogers, Alternate Universe - No Powers, Domestic Fluff, Established Relationship, Explicit Sexual Content, Implied Mpreg, M/M, Multi, Omega Tony Stark, Plot What Plot/Porn Without Plot, Polyamory
Language: English
Status: Completed
Published: 2019-02-16
Updated: 2019-02-16
Packaged: 2019-10-29 21:49:02
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,349
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17816114
Author URL: https://archiveofourown.org/users/dormantchrysalis/pseuds/dormantchrysalis
Summary: Steve pushes the door to their bedroom open and stands at the threshold, taking in the view. He isn’t disappointed.





	Equilibrium

The house is quiet when Steve returns from work that Tuesday afternoon, even though he knows it cannot be empty.

Bucky’s car is parked in its usual spot in the garage, as is expected – he only works in the early mornings on weekdays, at the dojo where he teaches mixed martial arts. He’s generally gone and back before Steve’s even showered following his morning run or Tony’s so much as stirred from the bed.

But even Tony’s car is parked in the driveway today, which _is_ , in fact, unusual. As far as Steve knows, his husband isn’t supposed to get off from work till 6pm today. It’s strange that he beat Steve home.

He looks around the empty living room, then heads to the dining area for a glass of water. A little gurgling sound comes from one of the bedrooms down the corridor. Steve smiles at that, soft and fond, and walks on socked feet towards the vibrantly painted door leading to the generous nursery room, pushing it open. Inside is a crib under a quietly-spinning baby mobile of rockets, stars, and moons. And there lies a bright-eyed baby, barely six months old, making a valiant effort at eating his own toes.

Steve walks in and bends over the crib, giving Peter a fond kiss on the cheek, at which Peter gurgles back at him, throwing spit bubbles around the soggy sock-clad feet he’s chewing. Steve laughs in joy at his son – so like Tony with his head of soft brown curls and his warm brown eyes, but with Steve’s pale Irish complexion – and bends down again to blow a raspberry on his stomach. He straightens, looking around for the digital eraser board they’ve hung nearby on one of the walls. It informs him, in Bucky’s messy scrawl, that Peter’s already been fed and changed and is not due to be done with his nap for another hour at least. Steve can see the sleepy pinch at the corner of Peter’s eyes now that he’s looking for it. He pats Peter’s belly for a couple of minutes, rubbing over it gently in a way that he knows soothes Peter, till he sees the wide brown eyes start to droop again. Peter starfishes out, eyes dropping closed as he starts to fall asleep. Steve watches the lovely cherubic face for a few more minutes before heading out in search of his husband and his best friend.

He has an idea where they might be and what they might be doing, seeing as they haven’t come to greet him for this long.

He walks upstairs, past their lounge area and their individual offices, finally stopping before the door to the master bedroom at the end of the hall. Now that he’s right in front of the door, he can hear them from the other side, voices muffled by the thick oak door, a dull, rhythmic _thump_ punctuating the silences.

Steve pushes the door to their bedroom open and stands at the threshold, taking in the view. He isn’t disappointed.

Tony’s splayed out on his back across on the bed, naked skin glowing in the dimmed sunlight filtering through the curtains of the large French windows to the side of the bed. His legs are wide open with Bucky kneeling between them, absolutely pounding him into the mattress as Tony groans and moans.

“Hey Steve,” Bucky says, turning his head to nod a greeting to Steve without even slowing down, before adjusting his grip on Tony’s legs slightly, gripping the backs of his thighs and pushing them open wider to better take his hard cock.

Tony gives a choked off moan, back arching a bit off the bed, his arms coming up to grip Bucky around the neck, pulling him down for a searing kiss. Bucky goes easily, readjusting the angle of Tony’s hips so he can grind into him, slow and deep. Tony’s left hand tangles in Bucky’s long hair, clutching at them, and Steve can see the diamond-studded gold wedding ring he slipped on Tony’s finger a few years ago, glinting in the afternoon sunlight.

He moves into the room, closing the door softly behind him, enjoying the view as he removes his tie and unbuttons the cuffs and collar of his shirt. Bucky and Tony part for air, Bucky straightening up again to put more force behind his thrusts, Tony’s whole body jerking with how deep and hard Bucky is taking him.

Steve walks over to the bed, kneeling on one knee to kiss Tony hello. Tony moans into his mouth, curses muffled by Steve’s tongue as Bucky speeds up his rhythm, slamming into Tony’s wet and open hole, the slap of his balls hitting Tony’s ass filling the room.

“How come you’re home so early?” Steve asks conversationally once he draws back from the kiss, moving his right hand to rove over Tony’s body, toying with his nipples, running teasing fingers over the muscles of his stomach. Tony’s body undulates under his hand, back arching off the bed again, breath coming in panting gasps. His pupils are unfocused and blown wide, and Steve wonders if Tony even heard him.

“His meeting with the Board finished early,” Bucky answers Steve’s question, grunting as his hips snap back and forth. “He got the major contract! Thought I’d get the celebrations going and give our genius a little reward.” He punctuates the statement with a particularly hard thrust and Tony’s eyes roll into his head.

He looks like he’s been fucked out of all words, flushed and panting, hips moving beautifully as he tries to take more of Bucky’s cock into him. He’s breathtaking. Steve, who has been half-hard since he opened the bedroom door, feels himself go fully erect.

Bucky clearly notices.

“Wanna join?” Bucky offers, slowing down a bit and slipping a finger suggestively into Tony’s omega hole, where it is spread wide and spasming around his plunging cock, wet with slick and precum and probably spit, knowing Bucky’s love for eating Tony out before fucking him. Tony groans louder, hips stuttering and losing their rhythm as he’s pushed closer to the edge. Bucky slips the finger in deeper, never faltering in the rhythm of his cock and Tony’s mouth falls open around a silent scream.  

“Can’t,” Steve answers regretfully, standing up and gesturing down at himself. His paint-splattered self, from where an idiot undergrad had upended blue paint on him while goofing around. Steve can feel the dried paint caking uncomfortably on his skin, crumbling at his joints and creases. He was going to give the kid a C- for the stupidity in class today anyway, but watching how Tony’s hole grips wet and hot around Bucky’s cock and fingers, Steve firmly decides it’ll be a D.

Bucky’s eyes rove over Steve, giving out a snort of laughter and nodding in acquiescence. “Go take a shower. I’ll keep him wet and open for you.”

Steve watches them for a few more minutes as Bucky picks up the pace, slowly driving Tony insane and clearly chasing his own orgasm, then hurries into the en-suite bathroom for a quick and vigorous shower, trying to resist taking his cock in hand to jerk off desperately as the sounds of fucking from the adjoining room filter in through the open bathroom door. He presses down hard on his cock as he hears Tony and Bucky come, hurrying through the scrubbing to strip as much of the paint off his skin as possible and then hopping out of the water.

He towels himself perfunctorily, dabbing lightly over his straining dick with a wince, then goes back into the bedroom, feeling flushed and stretched thin, more than ready to get his own cock into their omega’s warmth.

He is treated to the sight of a spent Tony lying on his side, Bucky behind him. From this vantage point, Steve can clearly see where they are still joined, Bucky’s knot stretching Tony’s hole wide open, the way Bucky’s balls shrink and relax in time with the pulsing at the root of his cock as he fills Tony with his seed. Tony’s taking deep, shuddering breaths, his lovely spent member flopped over his stomach, long ropes of his own release splattering his chest.

Steve’s fingers itch for his sketchbook.

The view before him is just so insanely gorgeous, the late afternoon light hushed as it streams through the soft curtains, Bucky’s pale hands contrasting with the gorgeous golden hue of Tony’s skin where it caresses his stomach, Bucky’s stubbled jaw leaving red tracks as his mouth brushes gentle kisses on Tony’s shoulder, Bucky’s giant knot looking impossibly large as it stretches Tony’s flushed and gaping hole. Steve would go hunt down his sketchbook, really, if not for the not-at-all-little problem between his legs demanding his attention.

(It wouldn’t be the first time he ditched his art in favor of his dick).

Steve climbs onto the bed and lies down on the other side of Tony, turning sideways and reaching out to take his face in his hand, leaning in to kiss him, slow and languid and wet. Tony whimpers a bit into his mouth, body shaking a bit from the aftershocks of his orgasm, letting out little moans every time Bucky’s knot moves inside him.

Bucky reaches down and lifts up Tony’s leg, spreading him open and presenting his flushed and knotted omega hole to Steve.

“Slide in,” he says in a husky voice, smirking slightly at Steve as Tony moans and shudders in response. “You know he can take it.”

Steve grins at Bucky, scooting his hips forward till his hot and straining cock rubs up against Tony’s stretched hole, where Bucky is still knotted and pulsing inside him. Tony’s mouth is open around a wordless groan, eyes closed anticipatorily, knowing what is coming, _eager_ for it.

Their omega likes nothing more than being mounted hard and knotted by both his alphas at the same time.

Tony really is perfect.

Steve rubs his cock over Tony’s hole, letting the tip catch on the open folds of his omega hole where Bucky’s knotting him, building up anticipation, making Tony shudder and buck between them, nearly crying with frustration.

“Ste- Steve,” Tony pants, coming again around Bucky’s knot, Steve able to _feel_ how Tony grips and gushes around Bucky’s cock as he rubs against them. “Steve, _please_.”

“Think he deserves the reward, don’t ya Steve?” Bucky murmurs hoarsely, latching his mouth to the back of Tony’s neck and starting a spectacular hickey. “He’s been such a good omega, so beautiful, so brilliant.”

“ _Please_ ,” Tony begs again, back arching in the throes of his orgasm, so wrung out now that his cock isn’t even leaking cum anymore. Steve wonders how long Bucky’s been fucking him today, if Tony’s already been driven to this level of desperation. He reaches forward to shove one, then two, then three fingers into Tony’s hole, opening him up wider around Bucky’s hard knot, motions hurried and perfunctory as his own cock strains to be inside that sinful wet heat. He lines up and with one smooth and forceful thrust slides all the way inside his husband.

Tony lets out a choked yell, back arching as he’s stretched so _wide_ , taking Steve’s large girth inside him with Bucky’s knot still completely filling him. Bucky moans, hips thrusting almost involuntarily, trying to fuck his knot even further as Tony’s hole gets impossibly hot and tight.

“Ahh, God,” Steve groans, trying not to come right away, squeezing the root of his cock to hold back a bit longer. Tony’s omega hole gushes around them as he comes yet again, his slick mixing with Bucky’s cum, bitten off moans and curses constantly falling from his mouth as both his alphas’ giant cocks struggle for purchase inside him.

Steve leans forward to kiss him hard and rough, opening Tony’s mouth with his tongue even as his cock opens up Tony’s omega hole, consuming him, devouring him. His hips stutter a bit before settling into an unforgiving rhythm, pounding into the tight _tight_ heat wrapped around his cock.

Bucky lets out a guttural groan, hips moving uselessly, knot still blown too large to be able to thrust inside Tony. Steve feels Bucky’s cock pulse under his, feels his cock engulfed in messy wetness, and he has to pause, has to _stop_ , as he nearly comes too soon _again_ , the sensations too erotic and heady to maintain any semblance of control. His mouth latches onto the side of Tony’s neck, teeth sinking into sweaty skin, fighting to push back his orgasm.

He disengages from Tony’s neck when he thinks he can hold on for a little longer, breathing hard like he’s just run a marathon, and lifts his head to see Bucky smirking at him, the smug bastard.

“Having trouble performing, Rogers?” Bucky quips, like the asshole he is. “Don’t worry if you can’t keep it up enough to show Tony a good time. I’ve been fucking him silly for the past hour. Tony’s had more than enough hard cocking for a day, haven’t you, love?” Bucky thrusts his hips once, and Steve feels the knot move and tug and catch inside Tony, pulsing as it fills him up again. Tony whimpers, high pitched and reedy, head thrown back as his cock gives a valiant attempt to come once more, several bites bruising purple on his neck where both Steve and Bucky latched onto him.

He is so absolutely _gorgeous_. Steve’s cock is so hard it hurts and he needs to move, _now_.

He pulls out, and in one swift movement flips Tony onto his back with his legs in the air, Bucky underneath, taking his weight. Steve settles between Tony’s open legs, lines up with his messy knotted hole leaking cum and slick again, and thrusts deep into him, hands wrapping around Tony’s thighs, keeping his legs spread wide to take them both.

Bucky tilts back Tony’s head and swallows his heated moans as Steve sets up a punishing rhythm, cock driving hard and fast through the mess they’ve made of their omega’s hole, Tony’s walls gripping around them, just _taking_ the absolute pounding he’s receiving. Bucky’s knot is still hard and _large_ inside Tony, nestled beside Steve’s cock, regularly flooding Tony’s hole with warm wetness. Steve watches where his own cock moves in and out of Tony, frothy with the fluids of the three of them, and Bucky pulses again, groan muffled into Tony’s mouth, and it’s just all so hot, so unbearably _beyond_ hot…

Steve pushes back Tony’s legs and folds him nearly double, pounding into him with abandon now, desperately chasing his own orgasm, and imagines the tableau they must present – Tony, lithe and golden and undone, caged in between two hulking muscular alphas spreading him wide, _using_ him for their own pleasure, two large knots buried in his omega hole and stretching him impossibly open and breeding him –

Steve feels feral orgasm rising up in his gut and he can’t stop it now if his life depended on it, hips stuttering in their rhythm, thrusting hard into Tony as he finally, _finally_ lets go and the world whites out around him.

He comes to a dozen dazed moments later, hips still thrusting weakly as his seed fills Tony up, the base of his cock swelling to lock him inside Tony’s omega hole, stretching it open even wider as it vies for space beside where Bucky’s knot is still blown wide inside their omega. Tony’s squeaks as his omega hole stretches to the limit, shuddering through the last of his orgasm, his poor over-stimulated cock releasing a few weak spurts of cum. Steve collapses on him like a marionette with cut strings, knot pulsing inside Tony.

“Ooof,” Bucky complains in a gruff, breathless voice. “Get off, you giant lump. You’re too heavy.”

“Can’t,” Steve groans into Tony’s neck, feeling Buck’s arms wrap around the two of them, too weak and spent to so much as lift his head.

Tony lifts a shaking arm to wind it through Steve’s sweaty hair, letting out quiet chuckles that rumble under Steve’s cheek as Bucky continues to grumble and jostle them. All three let out a moan as Bucky’s movements shifts their knots inside Tony, causing their cocks to pulse and cum again.

“Fucking hell,” Bucky groans, tilting Tony’s head back again to nip and suck on his lips. “You two will be the _death_ of me.”

Steve agrees with that sentiment.

They lie there in a sated, overheated pile of limbs for countless minutes, the two alphas’ knots working its way towards completion inside their omega. Steve turns his head to better watch Tony and Bucky kissing, a satisfied heat burning in his gut as he takes in Tony’s bitten red lips, how Bucky’s tongue opens him up to lazily taste him.

There’s a faint sound from across the room, so quiet he thinks for a moment that he imagined it. Then, unmistakably, a sniffling sounds from the direction of the baby monitor, threatening to turn into loud wailing if not attended to quickly.

Bucky pulls back from Tony’s mouth and turns a glare at Steve. “Your son has the absolute worst timing in the entire planet.”

Steve muffles a laugh into Tony’s neck. “Tony helped make him too, it’s not all my fault.”

“He’s definitely your son when he’s being a brat,” Tony sides with Bucky, like the giant hypocrite that he is, swatting Steve’s ass.

The sniffling builds steadily louder, and Bucky heaves a giant sigh.

“I have to do everything around here,” he grumbles, shifting and bunching the muscles under his shoulders till, with one powerful move, he’s flipped the three of them, Steve now at the bottom with Tony draped over his chest.

Bucky looms over them, thrusting his shrinking cock inside Tony’s used hole, spurting weakly inside him till the last of his knot goes down. With a grunt, he works his spent cock out of their omega, Tony twitching as a rush of cum slips out of his gaping hole, and Bucky finally pulls free.

Bucky bends down to press quick kisses to Tony’s shuddering shoulder and Steve’s flushed forehead, then heads out of the bedroom, picking up a pair of Steve’s discarded sweatpants from the floor as he goes. A few minutes later, they hear Bucky’s voice speaking in a soothing tone through the tinny speakers of the baby monitor, hushing and murmuring till the wails drop off to soft hiccups.

Steve runs soothing fingers over the warm, shuddering weight lying on his chest, knot still too large to pull out of Tony despite how much looser the omega’s spasming hole is without Bucky’s knot also filling him. His knot pumps more seed into the omega, the cum from two alphas mixing and leaking out of Tony’s omega hole in a sluggish trail. Steve, unable to resist, works his fingers into the open wetness, Tony loose enough to take three of Steve’s fingers right away.

“Ste- _eve_ ,” Tony moans brokenly, shuddering on top of him, too wrung out to even open his eyes to glare at his unapologetic alpha. Steve hides a grin in Tony’s neck, tilting his jaw to place gentle kisses along Tony’s jaw, two fingers toying idly with the well-fucked hole while they both wait for his knot to die down.

 “We did good,” Tony mumbles, the first coherent sentence he’s uttered in over thirty minutes.

“Hmm?”

“Bucky,” Tony clarifies, wriggling into Steve, the knot connecting them now more a sharing of affection than a searing embrace. Tony sighs contentedly as Steve’s mouth continues its trail, pressing kisses across Tony’s face. “When we decided to be brave enough to try for including him in our lives, to take a third mate. We did good, there.”

The afternoon is golden and peaceful, an intimate world built on the warmth of their intertwined bodies, the sounds of their son and other partner through the baby monitor a gentle background noise to complete the crystalline perfection of the moment.

Steve agrees.

 

**Author's Note:**

> Hope you all enjoyed this dose of pure sin! (⌒_⌒;) Tentatively planning a series with this, let's see how it goes. ^_^ Comments and kudos appreciated!


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